<template>
  <div>
    <!-- 评论列表 -->
    <div class="cmt-list" :class="isShowCmtbox ? 'art-cmt-container-2' : 'art-cmt-container-1'">
      <van-list
    v-model="loading"
    :finished="finished"
    finished-text="没有更多了"
    @load="onLoad"
    :immediate-check="false"
      >
   <!-- 评论的 Item 项 -->
      <div class="cmt-item" v-for="obj in commentArr" :key="obj.com_id">
        <!-- 头部区域 -->
        <div class="cmt-header">
          <!-- 头部左侧 -->
          <div class="cmt-header-left">
            <img :src="obj.aut_photo" alt="" class="avatar">
            <span class="uname">{{obj.aut_name}}</span>
          </div>
          <!-- 头部右侧 -->
          <div class="cmt-header-right">
            <van-icon name="like" size="16" color="red" v-if="obj.is_liking === true" @click="likeFn(true,obj)"/>
            <van-icon name="like-o" size="16" color="gray" v-else @click="likeFn(false,obj)"/>
          </div>
        </div>
        <!-- 主体区域 -->
        <div class="cmt-body">
           {{obj.content}}
        </div>
        <!-- 尾部区域 -->
        <div class="cmt-footer">{{timeAgo(obj.pubdate)}}</div>
      </div>
</van-list>
    </div>
    <!-- 发表评论 -->
    <div>
      <!-- 底部添加评论区域 - 1 -->
<div class="add-cmt-box van-hairline--top" v-if="isShowCmtbox === true">
    <van-icon name="arrow-left" size="0.48rem" @click="$router.back()" />
    <div class="ipt-cmt-div" @click="toggleShowFn">发表评论</div>
    <div class="icon-box">
        <van-badge :content="totalCount === 0 ? '' : totalCount" max = '99'>
            <van-icon name="comment-o" size="0.53333334rem" @click="commentClickFn"/>
        </van-badge>
        <van-icon name="star-o" size="0.53333334rem" />
        <van-icon name="share-o" size="0.53333334rem" />
    </div>
</div>

<!-- 底部添加评论区域 - 2 -->
<div class="cmt-box van-hairline--top" v-else>
    <textarea placeholder="友善评论、理性发言、阳光心灵" v-fofo @blur="blurFn" v-model.trim="comText"></textarea>
    <van-button type="default" :disabled="comText.length === 0" @click="sendFn">发布</van-button>
</div>
    </div>
  </div>
</template>

<script>
import {commentsListAPI,commentsLikingsAPI,commentDisLikingsAPI,sendCommentAPI} from '@/api/index'
import {timeAgo} from '@/utils/date.js'
export default {
    data () {
        return {
            offset: null, // 偏移量评论ID
            commentArr: [], // 评论列表
            isShowCmtbox: true, // 底部显示短的还是高的
            totalCount: 0, // 评论总数
            comText: '', // 评论的内容
            loading: false,
            finished: false,
            lastId: null // 分页
        }
    },
    async created () {
        const res = await commentsListAPI({
            id: this.$route.query.art_id // 文章id
        })
        console.log(res)
        this.commentArr = res.data.data.results
        this.totalCount = res.data.data.total_count || '' // 如果无评论数,给空字符串(防止0微标出现)
        this.lastId = res.data.data.last_id // 分页

        // 网页打开没有评论,res结果空数组
        if (res.data.data.results.length === 0) {
          this.finished = true
        }
    },
    methods: {
        timeAgo,
        // 评论小心心, 点赞或者取消点赞
      async likeFn (bool,commentObj) {
            if (bool === true) {
              // 用户点击红星 -> 取消点赞
              commentObj.is_liking = false
              await commentDisLikingsAPI({
                comId: commentObj.com_id
              })
            } else {
              // 用户点击了灰心 -> 点赞
              commentObj.is_liking = true
              await commentsLikingsAPI({
                comId: commentObj.com_id
              })
            }
        },
        // 显示评论输入框
        toggleShowFn () {
          this.isShowCmtbox = false
        },
        // 点击滑动到评论处
        commentClickFn () {
          // 比较方便的方法(既能滚动也能带动画)
          // 原生标签.scrollIntoView(), 让元素的标签滚动到屏幕的最上面
          // 为何选择like-box不选择第一条评论,因为头部导航会挡住
          document.querySelector('.like-box').scrollIntoView({
            behavior: 'smooth'
          })
        },
        // 输入框 - 失去焦点
        // 问题：点击发布按钮,发现点击事件不执行 - 排除代码问题
        // 原因：高的评论容器 - 在页面点击发布一瞬间,输入框失去了焦点被v-if和v-else销毁,导致点击事件没来得及执行
        // 解决：失去焦点时,变量值,在最后执行
        blurFn () {
          setTimeout(() => {
            this.isShowCmtbox = true
          },0)
        },
        // 发布按钮 - 点击事件
       async sendFn () {
          const res = await sendCommentAPI({
            artId: this.$route.query.art_id,
            content: this.comText
          })
          console.log(res)
          // 保存新评论对象到数组中
          this.commentArr.unshift(res.data.data.new_obj)
          // 数量 + 1
          this.totalCount++
          // 成功后,清除输入框内容
          this.comText = ''
        },
        // 底部加载更多
       async onLoad () {
          if (this.commentArr.length > 0) {
            // 请求下一页数据
            const res = await commentsListAPI({
            id: this.$route.query.art_id, // 文章id
            offset: this.lastId
        })
          console.log(res)
          this.commentArr = [...this.commentArr,...res.data.data.results]
          this.totalCount = res.data.data.total_count || '' // 如果无评论数,给空字符串(防止0微标出现)
          this.lastId = res.data.data.last_id // 分页

          if (res.data.data.last_id === null) {
            // 没有下一页
            this.finished = true
            }

            this.loading = false
          } else {
            this.loading = false
          }
        }
    }
}
</script>

<style scoped lang="less">
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}

/*美化 - 文章详情 - 底部的评论页面 */
// 外层容器
.art-cmt-container-1 {
  padding-bottom: 46px;
}
.art-cmt-container-2 {
  padding-bottom: 80px;
}

// 发布评论的盒子 - 1
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}

.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}

// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
